1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699
|
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/* rendering object for CSS "display: flex" and "display: -webkit-box" */
#ifndef nsFlexContainerFrame_h___
#define nsFlexContainerFrame_h___
#include <tuple>
#include "mozilla/dom/FlexBinding.h"
#include "mozilla/IntrinsicISizesCache.h"
#include "nsContainerFrame.h"
#include "nsILineIterator.h"
nsContainerFrame* NS_NewFlexContainerFrame(mozilla::PresShell* aPresShell,
mozilla::ComputedStyle* aStyle);
/**
* These structures are used to capture data during reflow to be
* extracted by devtools via Chrome APIs. The structures are only
* created when requested in GetFlexFrameWithComputedInfo(), and
* the structures are attached to the nsFlexContainerFrame via the
* FlexContainerInfo property.
*/
struct ComputedFlexItemInfo {
nsCOMPtr<nsINode> mNode;
nsRect mFrameRect;
/**
* mMainBaseSize is a measure of the size of the item in the main
* axis before the flex sizing algorithm is applied. In the spec,
* this is called "flex base size", but we use this name to connect
* the value to the other main axis sizes.
*/
nscoord mMainBaseSize;
/**
* mMainDeltaSize is the amount that the flex sizing algorithm
* adds to the mMainBaseSize, before clamping to mMainMinSize and
* mMainMaxSize. This can be thought of as the amount by which the
* flex layout algorithm "wants" to shrink or grow the item, and
* would do, if it was unconstrained. Since the flex sizing
* algorithm proceeds linearly, the mMainDeltaSize for an item only
* respects the resolved size of items already frozen.
*/
nscoord mMainDeltaSize;
nscoord mMainMinSize;
nscoord mMainMaxSize;
nscoord mCrossMinSize;
nscoord mCrossMaxSize;
mozilla::dom::FlexItemClampState mClampState;
};
struct ComputedFlexLineInfo {
nsTArray<ComputedFlexItemInfo> mItems;
nscoord mCrossStart;
nscoord mCrossSize;
nscoord mFirstBaselineOffset;
nscoord mLastBaselineOffset;
mozilla::dom::FlexLineGrowthState mGrowthState;
};
struct ComputedFlexContainerInfo {
nsTArray<ComputedFlexLineInfo> mLines;
mozilla::dom::FlexPhysicalDirection mMainAxisDirection;
mozilla::dom::FlexPhysicalDirection mCrossAxisDirection;
};
/**
* Helper class to get the orientation of a flex container's axes.
*/
class MOZ_STACK_CLASS FlexboxAxisInfo final {
public:
explicit FlexboxAxisInfo(const nsIFrame* aFlexContainer);
// Is our main axis the inline axis? (Are we 'flex-direction:row[-reverse]'?)
bool mIsRowOriented = true;
// Is our main axis in the opposite direction as mWM's corresponding axis?
// (e.g. RTL vs LTR)
bool mIsMainAxisReversed = false;
// Is our cross axis in the opposite direction as mWM's corresponding axis?
// (e.g. BTT vs TTB)
bool mIsCrossAxisReversed = false;
private:
// Helpers for constructor which determine the orientation of our axes, based
// on legacy box properties (-webkit-box-orient, -webkit-box-direction) or
// modern flexbox properties (flex-direction, flex-wrap) depending on whether
// the flex container is a "legacy webkit box".
void InitAxesFromLegacyProps(const nsIFrame* aFlexContainer);
void InitAxesFromModernProps(const nsIFrame* aFlexContainer);
};
/**
* This is the rendering object used for laying out elements with
* "display: flex" or "display: inline-flex".
*
* We also use this class for elements with "display: -webkit-box" or
* "display: -webkit-inline-box".
*
* Note: we represent the -webkit-box family of properties (-webkit-box-orient,
* -webkit-box-flex, etc.) as aliases for their -moz equivalents. And for
* -webkit-{inline-}box containers, nsFlexContainerFrame will honor those
* "legacy" properties for alignment/flexibility/etc. *instead of* honoring the
* modern flexbox & alignment properties. For brevity, many comments in
* nsFlexContainerFrame.cpp simply refer to these properties using their
* "-webkit" versions, since we're mostly expecting to encounter them in that
* form. (Technically, the "-moz" versions of these properties *can* influence
* layout here as well (since that's what the -webkit versions are aliased to)
* -- but only inside of a "display:-webkit-{inline-}box" container.)
*/
class nsFlexContainerFrame final : public nsContainerFrame,
public nsILineIterator {
public:
NS_DECL_FRAMEARENA_HELPERS(nsFlexContainerFrame)
NS_DECL_QUERYFRAME
// Factory method:
friend nsContainerFrame* NS_NewFlexContainerFrame(
mozilla::PresShell* aPresShell, ComputedStyle* aStyle);
// Forward-decls of helper classes
class FlexItem;
class FlexLine;
class FlexboxAxisTracker;
struct StrutInfo;
class CachedBAxisMeasurement;
class CachedFlexItemData;
struct SharedFlexData;
struct PerFragmentFlexData;
class FlexItemIterator;
// nsIFrame overrides
void Init(nsIContent* aContent, nsContainerFrame* aParent,
nsIFrame* aPrevInFlow) override;
void BuildDisplayList(nsDisplayListBuilder* aBuilder,
const nsDisplayListSet& aLists) override;
void MarkIntrinsicISizesDirty() override;
void Reflow(nsPresContext* aPresContext, ReflowOutput& aReflowOutput,
const ReflowInput& aReflowInput,
nsReflowStatus& aStatus) override;
nscoord IntrinsicISize(const mozilla::IntrinsicSizeInput& aInput,
mozilla::IntrinsicISizeType aType) override;
#ifdef DEBUG_FRAME_DUMP
nsresult GetFrameName(nsAString& aResult) const override;
#endif
Maybe<nscoord> GetNaturalBaselineBOffset(
mozilla::WritingMode aWM, BaselineSharingGroup aBaselineGroup,
BaselineExportContext) const override;
// Unions the child overflow from our in-flow children.
void UnionInFlowChildOverflow(mozilla::OverflowAreas&,
bool aAsIfScrolled = false);
// Unions the child overflow from all our children, including out of flows.
void UnionChildOverflow(mozilla::OverflowAreas&, bool aAsIfScrolled) final;
// nsContainerFrame overrides
bool DrainSelfOverflowList() override;
void AppendFrames(ChildListID aListID, nsFrameList&& aFrameList) override;
void InsertFrames(ChildListID aListID, nsIFrame* aPrevFrame,
const nsLineList::iterator* aPrevFrameLine,
nsFrameList&& aFrameList) override;
void RemoveFrame(DestroyContext&, ChildListID, nsIFrame*) override;
mozilla::StyleAlignFlags CSSAlignmentForAbsPosChild(
const ReflowInput& aChildRI,
mozilla::LogicalAxis aLogicalAxis) const override;
// Return aFlexItem's used 'align-self' value and the associated flags
// (safe/unsafe).
//
// Note: This method guarantees not to return StyleAlignFlags::NORMAL because
// it converts NORMAL to STRETCH.
std::pair<mozilla::StyleAlignFlags, mozilla::StyleAlignFlags>
UsedAlignSelfAndFlagsForItem(const nsIFrame* aFlexItem) const;
/**
* Helper function to calculate packing space and initial offset of alignment
* subjects in MainAxisPositionTracker() and CrossAxisPositionTracker() for
* space-between, space-around, and space-evenly.
* * @param aNumThingsToPack Number of alignment subjects.
* @param aAlignVal Value for align-content or
* justify-content.
* @param aFirstSubjectOffset Outparam for first subject offset.
* @param aNumPackingSpacesRemaining Outparam for number of equal-sized
* packing spaces to apply between each
* alignment subject.
* @param aPackingSpaceRemaining Outparam for total amount of packing
* space to be divided up.
*/
static void CalculatePackingSpace(
uint32_t aNumThingsToPack,
const mozilla::StyleContentDistribution& aAlignVal,
nscoord* aFirstSubjectOffset, uint32_t* aNumPackingSpacesRemaining,
nscoord* aPackingSpaceRemaining);
/**
* This property is created by a call to
* nsFlexContainerFrame::GetFlexFrameWithComputedInfo.
*/
NS_DECLARE_FRAME_PROPERTY_DELETABLE(FlexContainerInfo,
ComputedFlexContainerInfo)
/**
* This function should only be called on a nsFlexContainerFrame
* that has just been returned by a call to
* GetFlexFrameWithComputedInfo.
*/
const ComputedFlexContainerInfo* GetFlexContainerInfo() {
const ComputedFlexContainerInfo* info = GetProperty(FlexContainerInfo());
NS_WARNING_ASSERTION(info,
"Property generation wasn't requested. "
"This is a known issue in Print Preview. "
"See Bug 1157012.");
return info;
}
/**
* Return aFrame as a flex frame after ensuring it has computed flex info.
* @return nullptr if aFrame is null or doesn't have a flex frame
* as its content insertion frame.
* @note this might destroy layout/style data since it may flush layout.
*/
MOZ_CAN_RUN_SCRIPT_BOUNDARY
static nsFlexContainerFrame* GetFlexFrameWithComputedInfo(nsIFrame* aFrame);
/**
* Given a frame for a flex item, this method returns true IFF that flex
* item's inline axis is the same as (i.e. not orthogonal to) its flex
* container's main axis.
*
* (This method is only intended to be used from external
* callers. Inside of flex reflow code, FlexItem::IsInlineAxisMainAxis() is
* equivalent & more optimal.)
*
* @param aFrame a flex item (must return true from IsFlexItem)
* @return true iff aFrame's inline axis is the same as (i.e. not orthogonal
* to) its flex container's main axis. Otherwise, false.
*/
static bool IsItemInlineAxisMainAxis(nsIFrame* aFrame);
/**
* Returns true iff the given computed 'flex-basis' & main-size property
* values collectively represent a used flex-basis of 'content'.
* See https://drafts.csswg.org/css-flexbox-1/#valdef-flex-basis-auto
*
* @param aFlexBasis the computed 'flex-basis' for a flex item.
* @param aMainSize the computed main-size property for a flex item.
*/
static bool IsUsedFlexBasisContent(const mozilla::StyleFlexBasis& aFlexBasis,
const mozilla::StyleSize& aMainSize);
/**
* Callback for nsIFrame::MarkIntrinsicISizesDirty() on a flex item.
*/
static void MarkCachedFlexMeasurementsDirty(nsIFrame* aItemFrame);
bool CanProvideLineIterator() const final { return true; }
nsILineIterator* GetLineIterator() final { return this; }
int32_t GetNumLines() const final;
bool IsLineIteratorFlowRTL() final;
mozilla::Result<LineInfo, nsresult> GetLine(int32_t aLineNumber) final;
int32_t FindLineContaining(nsIFrame* aFrame, int32_t aStartLine = 0) final;
NS_IMETHOD FindFrameAt(int32_t aLineNumber, nsPoint aPos,
nsIFrame** aFrameFound, bool* aPosIsBeforeFirstFrame,
bool* aPosIsAfterLastFrame) final;
NS_IMETHOD CheckLineOrder(int32_t aLine, bool* aIsReordered,
nsIFrame** aFirstVisual,
nsIFrame** aLastVisual) final;
protected:
// Protected constructor & destructor
explicit nsFlexContainerFrame(ComputedStyle* aStyle,
nsPresContext* aPresContext)
: nsContainerFrame(aStyle, aPresContext, kClassID) {}
virtual ~nsFlexContainerFrame();
// Protected flex-container-specific methods / member-vars
/**
* This method does the bulk of the flex layout, implementing the algorithm
* described at: https://drafts.csswg.org/css-flexbox-1/#layout-algorithm
* (with a few initialization pieces happening in the caller, Reflow().
*
* (The logic behind the division of work between Reflow and DoFlexLayout is
* as follows: DoFlexLayout() begins at the step that we have to jump back
* to, if we find any visibility:collapse children, and Reflow() does
* everything before that point.)
*
* @param aTentativeContentBoxMainSize the "tentative" content-box main-size
* of the flex container; "tentative"
* because it may be unconstrained or may
* run off the page.
* @param aTentativeContentBoxCrossSize the "tentative" content-box cross-size
* of the flex container; "tentative"
* because it may be unconstrained or may
* run off the page.
*/
struct FlexLayoutResult final {
// The flex lines of the flex container.
nsTArray<FlexLine> mLines;
// The absolutely-positioned flex children.
nsTArray<nsIFrame*> mPlaceholders;
bool mHasCollapsedItems = false;
// The final content-box main-size of the flex container as if there's no
// fragmentation.
nscoord mContentBoxMainSize = NS_UNCONSTRAINEDSIZE;
// The final content-box cross-size of the flex container as if there's no
// fragmentation.
nscoord mContentBoxCrossSize = NS_UNCONSTRAINEDSIZE;
// The flex container's ascent for the "first baseline" alignment, derived
// from any baseline-aligned flex items in the startmost (from the
// perspective of the flex container's WM) flex line, if any such items
// exist. Otherwise, nscoord_MIN.
//
// Note: this is a distance from the border-box block-start edge.
nscoord mAscent = NS_UNCONSTRAINEDSIZE;
// The flex container's ascent for the "last baseline" alignment, derived
// from any baseline-aligned flex items in the endmost (from the perspective
// of the flex container's WM) flex line, if any such items exist.
// Otherwise, nscoord_MIN.
//
// Note: this is a distance from the border-box block-end edge. It's
// different from the identically-named-member FlexItem::mAscentForLast,
// which is a distance from the item frame's border-box block-start edge.
nscoord mAscentForLast = NS_UNCONSTRAINEDSIZE;
};
FlexLayoutResult DoFlexLayout(
const ReflowInput& aReflowInput,
const nscoord aTentativeContentBoxMainSize,
const nscoord aTentativeContentBoxCrossSize,
const FlexboxAxisTracker& aAxisTracker, nscoord aMainGapSize,
nscoord aCrossGapSize, nsTArray<StrutInfo>& aStruts,
ComputedFlexContainerInfo* const aContainerInfo);
/**
* If our devtools have requested a ComputedFlexContainerInfo for this flex
* container, this method ensures that we have one (and if one already exists,
* this method reinitializes it to look like a freshly-created one).
*
* @return the pointer to a freshly created or reinitialized
* ComputedFlexContainerInfo if our devtools have requested it;
* otherwise nullptr.
*/
ComputedFlexContainerInfo* CreateOrClearFlexContainerInfo();
/**
* Helpers for DoFlexLayout to computed fields in ComputedFlexContainerInfo.
*/
static void CreateFlexLineAndFlexItemInfo(
ComputedFlexContainerInfo& aContainerInfo,
const nsTArray<FlexLine>& aLines);
static void ComputeFlexDirections(ComputedFlexContainerInfo& aContainerInfo,
const FlexboxAxisTracker& aAxisTracker);
static void UpdateFlexLineAndItemInfo(
ComputedFlexContainerInfo& aContainerInfo,
const nsTArray<FlexLine>& aLines);
/**
* Helper to query flex item's consumed block-size.
*/
static nscoord FlexItemConsumedBSize(const FlexItem& aItem);
#ifdef DEBUG
void SanityCheckAnonymousFlexItems() const;
#endif // DEBUG
/**
* Construct a new FlexItem for the given child frame, directly at the end of
* aLine.
*
* Before returning, this method also processes the FlexItem to resolve its
* flex basis (including e.g. auto-height) as well as to resolve
* "min-height:auto", via ResolveAutoFlexBasisAndMinSize(). (Basically, the
* constructed FlexItem will be ready to participate in the "Resolve the
* Flexible Lengths" step of the Flex Layout Algorithm.)
* https://drafts.csswg.org/css-flexbox-1/#algo-flex
*
* Note that this method **does not** update aLine's main-size bookkeeping to
* account for the newly-constructed flex item. The caller is responsible for
* determining whether this line is a good fit for the new item. If so, the
* caller should update aLine's bookkeeping (via
* FlexLine::AddLastItemToMainSizeTotals), or move the new item to a new line.
*/
void GenerateFlexItemForChild(FlexLine& aLine, nsIFrame* aChildFrame,
const ReflowInput& aParentReflowInput,
const FlexboxAxisTracker& aAxisTracker,
const nscoord aTentativeContentBoxCrossSize);
/**
* This method looks up cached block-axis measurements for a flex item, or
* does a measuring reflow and caches those measurements.
*
* This avoids exponential reflows - see the comment above the
* CachedBAxisMeasurement struct.
*/
const CachedBAxisMeasurement& MeasureBSizeForFlexItem(
FlexItem& aItem, ReflowInput& aChildReflowInput);
/**
* This method performs a "measuring" reflow to get the content BSize of
* aFlexItem.Frame() (treating it as if it had a computed BSize of "auto"),
* and returns the resulting BSize measurement.
* (Helper for ResolveAutoFlexBasisAndMinSize().)
*/
nscoord MeasureFlexItemContentBSize(FlexItem& aFlexItem,
bool aForceBResizeForMeasuringReflow,
const ReflowInput& aParentReflowInput);
/**
* This method resolves an "auto" flex-basis and/or min-main-size value
* on aFlexItem, if needed.
* (Helper for GenerateFlexItemForChild().)
*/
void ResolveAutoFlexBasisAndMinSize(FlexItem& aFlexItem,
const ReflowInput& aItemReflowInput,
const FlexboxAxisTracker& aAxisTracker);
/**
* Partially resolves "min-[width|height]:auto" and returns the resulting
* value. By "partially", I mean we don't consider the min-content size (but
* we do consider the main-size and main max-size properties, and the
* preferred aspect ratio). The caller is responsible for computing &
* considering the min-content size in combination with the partially-resolved
* value that this function returns.
*
* Basically, this function gets the specified size suggestion; if not, the
* transferred size suggestion; if both sizes do not exist, return
* nscoord_MAX.
*
* Spec reference: https://drafts.csswg.org/css-flexbox-1/#min-size-auto
* (Helper for ResolveAutoFlexBasisAndMinSize().)
*/
nscoord PartiallyResolveAutoMinSize(
const FlexItem& aFlexItem, const ReflowInput& aItemReflowInput,
const FlexboxAxisTracker& aAxisTracker) const;
/**
* This method:
* - Creates FlexItems for all of our child frames (except placeholders).
* - Groups those FlexItems into FlexLines.
* - Returns those FlexLines in the outparam |aLines|.
*
* This corresponds to "Collect flex items into flex lines" step in the spec.
* https://drafts.csswg.org/css-flexbox-1/#algo-line-break
*
* For any child frames which are placeholders, this method will instead just
* append that child to the outparam |aPlaceholders| for separate handling.
* (Absolutely positioned children of a flex container are *not* flex items.)
*/
void GenerateFlexLines(const ReflowInput& aReflowInput,
const nscoord aTentativeContentBoxMainSize,
const nscoord aTentativeContentBoxCrossSize,
const nsTArray<StrutInfo>& aStruts,
const FlexboxAxisTracker& aAxisTracker,
nscoord aMainGapSize,
nsTArray<nsIFrame*>& aPlaceholders,
nsTArray<FlexLine>& aLines, bool& aHasCollapsedItems);
/**
* Generates and returns a FlexLayoutResult that contains the FlexLines and
* some sizing metrics that should be used to lay out a particular flex
* container continuation (i.e. don't call this on the first-in-flow).
*/
FlexLayoutResult GenerateFlexLayoutResult();
/**
* Resolves the content-box main-size of a flex container frame,
* primarily based on:
* - the "tentative" main size, taken from the reflow input ("tentative"
* because it may be unconstrained or may run off the page).
* - the sizes of our lines of flex items.
*
* We assume the available block-size is always *unconstrained* because this
* is called only in flex algorithm to measure the flex container's size
* without regards to pagination.
*
* Guaranteed to return a definite length, i.e. not NS_UNCONSTRAINEDSIZE,
* aside from cases with huge lengths which happen to compute to that value.
*
* This corresponds to "Determine the main size of the flex container" step in
* the spec. https://drafts.csswg.org/css-flexbox-1/#algo-main-container
*
* (Note: This function should be structurally similar to
* ComputeCrossSize().)
*/
nscoord ComputeMainSize(const ReflowInput& aReflowInput,
const FlexboxAxisTracker& aAxisTracker,
const nscoord aTentativeContentBoxMainSize,
nsTArray<FlexLine>& aLines) const;
nscoord ComputeCrossSize(const ReflowInput& aReflowInput,
const FlexboxAxisTracker& aAxisTracker,
const nscoord aTentativeContentBoxCrossSize,
nscoord aSumLineCrossSizes, bool* aIsDefinite) const;
/**
* Compute the size of the available space that we'll give to our children to
* reflow into. In particular, compute the available size that we would give
* to a hypothetical child placed at the IStart/BStart corner of this flex
* container's content-box.
*
* @param aReflowInput the flex container's reflow input.
* @param aBorderPadding the border and padding of this frame with the
* assumption that this is the last fragment.
*
* @return the size of the available space for our children to reflow into.
*/
mozilla::LogicalSize ComputeAvailableSizeForItems(
const ReflowInput& aReflowInput,
const mozilla::LogicalMargin& aBorderPadding) const;
void SizeItemInCrossAxis(ReflowInput& aChildReflowInput, FlexItem& aItem);
/**
* This method computes the metrics to be reported via the flex container's
* ReflowOutput & nsReflowStatus output parameters in Reflow().
*
* @param aContentBoxSize the final content-box size for the flex container as
* a whole, converted from the flex container's
* main/cross sizes. The main/cross sizes are computed
* by DoFlexLayout() if this frame is the
* first-in-flow, or are the stored ones in
* SharedFlexData if this frame is a not the
* first-in-flow.
* @param aBorderPadding the border and padding for this frame (possibly with
* some sides skipped as-appropriate, if we're in a
* continuation chain).
* @param aConsumedBSize the sum of our content-box block-size consumed by our
* prev-in-flows.
* @param aMayNeedNextInFlow true if we may need a next-in-flow because our
* effective content-box block-size exceeds the
* available block-size.
* @param aMaxBlockEndEdgeOfChildren the maximum block-end edge of the
* children of this fragment in this frame's
* coordinate space (as returned by
* ReflowChildren()).
* @param aChildrenStatus the reflow status of children (as returned by
* ReflowChildren()).
* @param aFlr the result returned by DoFlexLayout.
* Note: aFlr is mostly an "input" parameter, but we use
* aFlr.mAscent as an "in/out" parameter; it's initially the
* "tentative" flex container ascent computed in DoFlexLayout; or
* nscoord_MIN if the ascent hasn't been established yet. If the
* latter, this will be updated with an ascent derived from the
* (WM-relative) startmost flex item (if there are any flex
* items). Similar for aFlr.mAscentForLast.
*/
void PopulateReflowOutput(
ReflowOutput& aReflowOutput, const ReflowInput& aReflowInput,
nsReflowStatus& aStatus, const mozilla::LogicalSize& aContentBoxSize,
const mozilla::LogicalMargin& aBorderPadding,
const nscoord aConsumedBSize, const bool aMayNeedNextInFlow,
const nscoord aMaxBlockEndEdgeOfChildren,
const nsReflowStatus& aChildrenStatus,
const FlexboxAxisTracker& aAxisTracker, FlexLayoutResult& aFlr);
/**
* Perform a final Reflow for our child frames.
*
* @param aContainerSize this frame's tentative physical border-box size, used
* only for logical to physical coordinate conversion.
* @param aAvailableSizeForItems the size of the available space for our
* children to reflow into.
* @param aBorderPadding the border and padding for this frame (possibly with
* some sides skipped as-appropriate, if we're in a
* continuation chain).
* @param aSumOfPrevInFlowsChildrenBlockSize See the comment for
* SumOfChildrenBlockSizeProperty.
* @param aFlr the result returned by DoFlexLayout.
* @param aFragmentData See the comment for PerFragmentFlexData.
* Note: aFragmentData is an "in/out" parameter. It is
* initialized by the data stored in our prev-in-flow's
* PerFragmentFlexData::Prop(); its fields will then be
* updated and become our PerFragmentFlexData.
* @return nscoord the maximum block-end edge of children of this fragment in
* flex container's coordinate space.
* @return nsReflowStatus the reflow status of children (i.e. flex items). If
* any child had an incomplete reflow status, then this
* will be Incomplete. Otherwise, if any child had an
* overflow-incomplete reflow status, this will be
* OverflowIncomplete.
*/
std::tuple<nscoord, nsReflowStatus> ReflowChildren(
const ReflowInput& aReflowInput, const nsSize& aContainerSize,
const mozilla::LogicalSize& aAvailableSizeForItems,
const mozilla::LogicalMargin& aBorderPadding,
const FlexboxAxisTracker& aAxisTracker, FlexLayoutResult& aFlr,
PerFragmentFlexData& aFragmentData);
/**
* Moves the given flex item's frame to the given LogicalPosition (modulo any
* relative positioning).
*
* This can be used in cases where we've already done a "measuring reflow"
* for the flex item at the correct size, and hence can skip its final reflow
* (but still need to move it to the right final position).
*
* @param aItem The flex item whose frame should be moved.
* @param aFramePos The position where the flex item's frame should
* be placed. (pre-relative positioning)
* @param aContainerSize The flex container's size (required by some methods
* that we call, to interpret aFramePos correctly).
*/
void MoveFlexItemToFinalPosition(const FlexItem& aItem,
const mozilla::LogicalPoint& aFramePos,
const nsSize& aContainerSize);
/**
* Helper-function to reflow a child frame, at its final position determined
* by flex layout.
*
* @param aAxisTracker A FlexboxAxisTracker with the flex container's axes.
* @param aReflowInput The flex container's reflow input.
* @param aItem The flex item to be reflowed.
* @param aFramePos The position where the flex item's frame should
* be placed. (pre-relative positioning)
* @param aIsAdjacentWithBStart True if aFramePos is adjacent with the flex
* container's content-box block-start edge.
* @param aAvailableSize The available size to reflow the child frame (in the
* child frame's writing-mode).
* @param aContainerSize The flex container's size (required by some methods
* that we call, to interpret aFramePos correctly).
* @return the child frame's reflow status.
*/
nsReflowStatus ReflowFlexItem(const FlexboxAxisTracker& aAxisTracker,
const ReflowInput& aReflowInput,
const FlexItem& aItem,
const mozilla::LogicalPoint& aFramePos,
const bool aIsAdjacentWithBStart,
const mozilla::LogicalSize& aAvailableSize,
const nsSize& aContainerSize);
/**
* Helper-function to perform a "dummy reflow" on all our nsPlaceholderFrame
* children, at the container's content-box origin.
*
* This doesn't actually represent the static position of the placeholders'
* out-of-flow (OOF) frames -- we can't compute that until we've reflowed the
* OOF, because (depending on the CSS Align properties) the static position
* may be influenced by the OOF's size. So for now, we just co-opt the
* placeholder to store the flex container's logical content-box origin, and
* we defer to nsAbsoluteContainingBlock to determine the OOF's actual static
* position (using this origin, the OOF's size, and the CSS Align
* properties).
*
* @param aReflowInput The flex container's reflow input.
* @param aPlaceholders An array of all the flex container's
* nsPlaceholderFrame children.
* @param aContentBoxOrigin The flex container's logical content-box
* origin (in its own coordinate space).
* @param aContainerSize The flex container's size (required by some
* reflow methods to interpret positions correctly).
*/
void ReflowPlaceholders(const ReflowInput& aReflowInput,
nsTArray<nsIFrame*>& aPlaceholders,
const mozilla::LogicalPoint& aContentBoxOrigin,
const nsSize& aContainerSize);
/**
* Helper to implement IntrinsicISize().
*/
nscoord ComputeIntrinsicISize(const mozilla::IntrinsicSizeInput& aInput,
mozilla::IntrinsicISizeType aType);
/**
* Cached values to optimize IntrinsicISize().
*/
mozilla::IntrinsicISizesCache mCachedIntrinsicSizes;
/**
* Cached baselines computed in our last reflow to optimize
* GetNaturalBaselineBOffset().
*/
// Note: the first baseline is a distance from our border-box block-start
// edge.
nscoord mFirstBaseline = NS_INTRINSIC_ISIZE_UNKNOWN;
// Note: the last baseline is a distance from our border-box block-end edge.
nscoord mLastBaseline = NS_INTRINSIC_ISIZE_UNKNOWN;
};
#endif /* nsFlexContainerFrame_h___ */
|